Three steps to a cooler planet: What a gas

We’ve recently discovered a 100-year supply of cheap, clean-burning natural gas right underneath our feet. Improved technology allows us to tap this previously inaccessible fuel reserve, and we’ve already accessed so much of it that gas prices have dropped to near-record lows.

We can use gas to heat our homes, and, with some retooling of our industry and infrastructure, we can use it to run our vehicles and generate our electricity as well. And burning gas releases so much less carbon dioxide into the atmosphere than burning coal and oil does, that gas will serve as a “bridge fuel,” allowing us to delay the onset of serious global warming until technological breakthroughs make renewable power feasible.

So you had better call your stockbroker today – no, this minute – and invest in “gas-age” technologies, before you find yourself left out of the coming gas boom!

Oh, and one more thing: If you believe all that, I have a bridge of my own to sell you.

That’s because it turns out that most of the enthusiastic babble about America’s natural-gas bonanza is based on dubious information, and, worse, on a failure to connect some critical dots in the energy/global warming conundrum. Our natural gas reserves aren’t nearly as extensive as hoped (or hyped), the new gas-extraction technology causes environmental problems, and, most important, delaying the transition to renewable energy by relying on natural gas can actually hasten the onset of global warming’s worst effects.

It turns out that there is a difference, a big difference, between what the gas industry calls “proved” U.S. gas reserves, amounting to 11 years’ worth at 2010 consumption levels; “proved plus possible” reserves, 21 years’ worth; and “speculative” reserves, estimated at 95 years’ worth. Realistic expectations are for the current glut in gas supplies, which is due largely to the advent of hydraulic, rock-fracturing, gas-extraction technology (“fracking”) and the revival of old wells, to last between 11 and 21 years – after which gas prices could take a huge leap.

So for the nation, corporations or individuals to make major investments in medium- to long-term gas-based technology such as automotive manufacturing equipment and power plants is premature, if not foolish. Similarly, investing in gas fields and especially gas-extraction technology is fraught with risk, as fracking causes water and air pollution and minor earthquakes – and thus could be subject to strict environmental regulation which would significantly reduce profitability.

However, short-term profitability aside, the really poor investment for society is buying into the idea that using natural gas as our principal energy source will postpone the serious effects of global warming. That might have been true if we had created a gas-based energy economy three decades ago, when the threat of global warming was first widely recognized.

But now our window of opportunity to stay below the dangerous global warming threshold of 450 parts per million of atmospheric CO2 is almost closed. We are already at 397 ppm, and climbing at the rate of about 2 ppm per year. So we have, at most, 25 years to stay below 450 ppm using our current energy mix of coal, oil and gas.

Meanwhile, it turns out that natural gas is hardly close to “greenhouse neutral,” as it has an overall global-warming effect of about 50 percent of that of coal and oil. (This figure includes about 43 percent of the carbon emissions of coal, 30 percent that of oil and the pre-combustion leakage of gas, which is 20 times as potent a greenhouse gas as CO2, into the atmosphere.)

So even if, in the most optimistic (and unlikely) of scenarios, we could completely retune our energy economy to be primarily reliant on natural gas in 20 years, it would be too late to delay crossing the 450 threshold by more than a few years. In 20 years we’ll be at least at 440 ppm, and a gas economy would push us over 450 within a decade after that.

Philip S. Wenz, who grew up in Durango and Boulder, now lives in Corvallis, Ore., where he teaches and writes about environmental issues. Reach him via e-mail through his website, www.your-ecological-house.com.